They may have posted the item but simply not marked it as posted. If they are newish, they may not realize that they need to do this nor the significance of doing so. If English is their second language, they may not understand what you mean by a tracking number, or they may have posted your item without one (if it was a large letter) or they simply may not have kept a record of it.
On the bright side, they are at least communicating with you.
Also remember that if the item has been posted, that the actual shipping time and processes are out of the sellers' control, so it might be a bit mean to penalize either their feedback or DSR's for something out of their control. I recently had a situation where it took 13 days for a package to arrive after the seller had lodged it, and this could be verified as the tracking number did show that Australia Post had accepted it on a particular date. That item would usually take a maximum of two business days to arrive between the two addresses involved.
I do understand your concern, so please keep in mind the option of commencing an INR (Item Not Received) dispute through PayPal if you availed yourself to that method of payment. Also keep in mind the time limitation of doing so which is 45 days after payment, I believe.
Best of Luck.
Some people can go their whole lives and never really live for a single minute.
